flywheel and coupler?

[gchaney]

I have an older 73 boat that I am repowering I removed a Mercruiser 5.0 with the old triangular coupler. I got another much newer 93ish 5.0 from a local shop and bought the conversion coupler for it but come to find out it had a hole in one piston. So out I go for a new engine. I picked up a Mercruiser 260 that was advertised as being newer than i am now thinking it is. question is old engine had a triangle coupler the conversion coupler I had for the middle engine does not fit the new engine and the newest engine has a third hub style coupler that bolts to the crank studs along with the smaller flywheel (12") First what hub do I need to use second do I need to convert to a 14 in flywheel?

Also if any one could help me narrow down what engine I have it would be appreciated I have narrowed it down to about 82 through 86
all the info is
MCM 260
Mercruiser serial # 6774634
GM casting # 14010207

Thanks

[achris]

MCM 260
Mercruiser serial # 6774634

1984.